A rare phenomenon that occurs once out of two million cases in the world of births and children, where conjoined twins were born in Indonesia as if they were fused together like a "spider".

In detail, the twins were born in 2018 with three legs, four arms, and one penis, and they share the same bladder and intestines.

Only a small number of this rare case of conjoined twins were recorded, and the condition of the boys was mentioned this week in an American medical journal.

After struggling during pregnancy and childbirth, the two children were unable to sit and were forced to lie flat during the first three years of their lives.

A team of surgeons performed an arduous operation to amputate their third leg and stabilize the hip and pelvic bones so that the twins could sit upright.

The Indonesian twins suffer from a condition known as "Ichiopagos Tripos", meaning that the two brothers are joined at the pelvic area, and were born with four working arms, two working legs, and one disabled leg.

The twins' parents had no family history of medical problems, and their mother did not report any complications during her pregnancy.